1. Field of the Invention
This disclosure relates to a navigation system that searches for a guide route from the position of user's vehicle to a destination and performs guidance along the guide route, namely, guide the user to the destination along the guide route, and in particular, relates to a guidance operation of the navigation system when the guide route or destination includes a ferry route or a railroad.
2. Description of the Related Art
A navigation system supports guidance along a guide route including a ferry route or a railroad other than a road. For example, Japanese Unexamined Patent Application Publication No. 2004-286518 discloses a method for guidance along a guide route using a ferry route. In this case, map data stored in a navigation system includes ferry boarding and alighting place position data regarding ferry boarding and alighting places in various locations, ferry data regarding available ferries in various locations, and ferry route data regarding ferry routes between ferry boarding and alighting places. On the basis of the above-described data items, a ferry boarding position and a ferry alighting position are estimated and guidance along a guide route is performed.
FIG. 1A illustrates an operation screen displayed during a destination setting operation of a related-art navigation system. When a user wants to use a ferry route or board a ferry, the user can select a ferry route as a destination (including a passing point). If the user has known the name of a ferry route or a ferry route terminal, the user can retrieve a destination using text on a menu screen. However, if the user does not know the name thereof, a map scroll screen as shown in FIG. 1A is displayed. The user selects a desired ferry route or a location on the ferry route while scrolling the map screen. Particularly, in Europe and the United States, the names of roads are often used in retrieving and setting a destination. A ferry route can also be selected as a type of road name.
The map screen includes a departure terminal 1 of the ferry route, an arrival terminal 2 thereof, boundaries 3 between land and water, a mark M indicating the position of user's vehicle (hereinafter, also referred to as “vehicle position”), and a ferry route F indicated by a broken line. When using the ferry route, the user selects a place on or near the ferry route F. Consequently, the navigation system recognizes that the ferry route F is set as a destination G, searches for a guide route Y from the vehicle position (or a starting location) to the destination G, and performs guidance along the guide route Y.
In the case where a location on the ferry route is set to a destination, however, the ignition of the user's vehicle is turned off while the vehicle is on board the ferry. Unfortunately, therefore, the navigation system cannot determine whether the vehicle has reached the destination G on the ferry route. Disadvantageously, when the ignition of the vehicle is turned on a road 5 linked to the arrival terminal 2 of the ferry route, the navigation system performs rerouting (re-searching) to again search for a route from the vehicle position M to the destination G, as shown in FIG. 1C.